Simplify the following expression: $k = \dfrac{a - 8}{5a - 4} + \dfrac{-6a + 9}{5a - 4}$
Solution: Since the expressions have the same denominator we simply combine the numerators: $k = \dfrac{a - 8 - 6a + 9}{5a - 4}$ Combine like terms: $k = \dfrac{-5a + 1}{5a - 4}$